Digestibility of okara-tempe protein in rats

Abstract

Okara-tempc (OT) is fermented okara (OC) by Rhizopus oligosporus (a fungus to make Tempe). In this paper, the effects of fermentation on the digestibility of OC protein were studied by using rats. By comparing OT with OC in respect of free amino acid content and the distribution of molecular weight of proteins, OT contained more free amino acids and lower molecular weight proteins than OC. The results suggest that some parts of OT proteins are decomposed into low molecular weight substances by the fermentation of OC. On optical micrograph of the digestive residue from rats fed on OT or OC diets which contained OT or OC proteins as the only source, the proteins in the cecum residue of OT diet were not detected appreciably, but those of OC diet were clearly observed. In the feces residue of OT or OC diets, any protein was not observed. It is presumed that both proteins of OT and OC will be completely digested, and OT protein will be digested easier than OC protein in rats.